Maamar Mordechai points out that, when the Jews were in Egypt, the ten plagues occurred for one month each. That being the case, the second to last plague, that of darkness, happened one month before Passover, which would mean it fell in Adar. Haman assumed the darkness was a plague that hurt the Jews since so many of them died then (see Rashi to Shemos 10:22 and 13:18). After all, four fifths of the Jews died in Egypt because they did not believe in their upcoming rescue. H-Shem killed these unfortunates during the plague of darkness to avoid the Egyptians seeing this, and assuming the Jews’ G-d is no longer with them.1 The Jews in Persia, by attending Achashverosh’s party, indicated that they, too, lost faith in their redemption, and this is why the lots falling on Adar so pleased Haman.
Adar is also the month when Moshe died. According to the Talmud (Megillah 13b), Haman knew this because it is so written in the end of Devarim (34:8) and can be calculated from the book of Yehoshua. According to our tradition, the seventh of Adar, his date of death, is also his date of birth. Rabbi Mendel Weinbach writes that Haman did not know this because, as opposed to his date of birth, his date of death is only found in the Oral Torah.
The Abudraham calculates that Adar 13 would mark the end of the seven-day mourning period (shiva) for Moshe. According to the Maharsha, that seven-day period of mourning continues in some mystical way the merits of the mourned. After that point, the dead only receive merit of others step up to take over their spiritual roles. Interestingly, Rabbi Dovid Feinstein notes that, Moshe having been born on 7 Adar, his bris (circumcision) would have been on 14 Adar, Purim!2
1It bespeaks a certain callousness that the Egyptians seemed not to notice the sudden disappearance of several million people.
2However, since Moshe was born complete and circumcised (Talmud, Sotah 12a), his bris would only require a symbolic pin-prick of blood called “hatafas dam bris” (Shulchan Aruch Yoreh Deah 262:1 and 264:1), and this procedure would not be help on a Shabbos (Shulchan Aruch Yoreh Deah 260:2 and 263:1). Therefore, Moshe’s symbolic bris was held on the following day, Shushan Purim.
According to the Targum Sheini’s interpretive translation, Haman’s oldest son, Shimshi, cast the pur.
The Malbim writes that the lot was cast for Haman – it decided when he would die since this plan to kill the Jews led to his execution (see below Esther 7:10).
The Chassam Sofer and the Me’am Loez write that Haman saw himself on top, and the Jews beneath him. Unfortunately for Haman, he did not interpret this correctly, as it was pointing to his hanging from the tree, and Mordechai beneath him, standing safely on the ground.
The Maharal says that Haman did not throw the lots himself for two reasons. The first is that he knew he was not a spiritually sensitive person. He therefore asked someone else to interpret the lots. The second reason is that he knew he had a subjective bias in the result. As such, his own subjectivity would subconsciously color his interpretation of the final result of the lots tossed. Perhaps these two answers are really one and the same. One cannot be a spiritually attuned person with biases. The more spiritual one becomes, the more objective one becomes. The entire goal of spirituality is to realize that our own wants should not have significance.
The Ben Ish Chai points out that the way Jews escape annihilation is through their performance of mitzvos, of which Torah study is the greatest (see Mishnah, Peah 1:1). That being the case, the Ben Ish Chai interprets our verse in a novel manner by writing that the lots cast pointed to the solution to Haman’s challenge being “lifnei Haman” the letters preceding the letters in Haman’s name in the Hebrew alphabet. The letters before hey (dales), mem (lamed), and nun (mem) can form the word “lamed,” (“learn”).
The Sfas Emes writes that Haman felt he needed to pick the right day of the week, as well as the correct month. Since, the days of the week represent the natural cycle established in the seven days of Creation, and every culture has its own fashion for establishing and measuring months, days represent a variable given Divinely. Months, however, represent a variable provided by people. Haman therefore thought the rabbis, who established the Jewish months (as mentioned above), were prone to error. Hence, Haman felt he could not be successful against H-Shem, Who established the days, but could be successful against the rabbis, who in his view represented imperfect, fallible men.
Megillas Sesarim writes that the word “pur,” coming from the foreign language of the Persian nation that had dominion over the Jews, has a negative connotation. Had the verse used the word “goral,” it would have had a positive connotation – especially with its allusions to the Yom Kippur service. Since the lot decided when the ideal time to massacre the Jews, the verse uses the Persian word.
On the other hand, since the lots also helped precipitate Haman’s downfall, the verse uses the Hebrew word, as well. In a deeper answer, the Pachad Yitzchak writes that the Jewish people always had two kinds of adversaries in their history – the four nations in which they were exiled, and the seven Canaanite nations they had to eject upon entry to the Holy Land. Therefore, he writes, “pur” is translated to emphasize the dual nature of Haman, in that he was both (as an Amalekite) from the seven nations in Israel and (as a Persian officer) from the four nations of exile.
Haman’s motivation for casting lots depends on what those lots were. According to the Vilna Gaon, Haman wanted to see when his plan would be most spiritually effective. He wanted to find the time that the Jews were at their spiritual weakest. He found Adar appealing because the Jews had no Holy Day for which to prepare, and no special merit to protect them, so were thus spiritually weak then. If that is the case, why then was Haman not successful? Because, says the Vilna Gaon, “ein mazal b’Yisroel” (“Jews have no [effects of] constellations”) (Talmud, Shabbos 156a). What this means is that, with Torah, Jewish people can channel the natural astrological influence of the horoscope.
If these lots are like our contemporary dice, opposite sides add up to seven. One is opposite to six, four is opposite to three, etc. Midrash Talpios says that, instead of numbers, Haman’s dice have Hebrew letters. Therefore, in gematria, if there is an aleph on one side, its opposite side had a vuv. Haman cast the dice three times. The dice read aleph, then gimmel, then gimmel again. This spells “Agag,” king of Amalek conquered by King Shaul (as mentioned previously). On the bottom of that combination would be a vuv, daled, and daled. A combination of these letters spells “David,” and Haman thought this meant Agag would succeed against David. In other words, Haman was under the impression that the lots he rolled predicted his victory over the Jews.
Ben Ish Chai says that Haman was so arrogant that he did not even consider the letters spelling out David. Rather, Haman was too busy noticing that the gematria of David (4+6+4) is 14, with a mispar katan1 of five. The mispar katan of Haman’s name is also five (5+40+50=95).
According to Rabbi Yehonason Eibshutz, Haman’s lottery consisted of his writing on separate papers all of the days of the year. After he chose a particular date (Adar 13th), he wanted to verify that this was not just a random date. He then got twelve papers with the twelve months of the year. That paper matched up to Adar. Class participant RS pointed out that the days of the solar year are also 365, which also has a mispar katan equal to Haman’s name.
Rabbi Eliezer Ashkenazi says Haman realized that the Jews were weak and in exile. He threw lots to find his one spiritual strength in relation to the spiritual strength of the Jewish people.
1A “mispar katan” is a form of gematria in which one adds all the numerals in a number until one arrives at a one-numeral number. For instance, the mispar katan of 19 is 1+9, which is 10. Since this is not a single-numeral number, the process is repeated with these numerals thus: 1+0, until one arrives at 1. Therefore, the mispar katan of 19 is 1.